Megalania (Varanus prisca) was a giant monitor lizard that lived in southern Australia. It was part of a species of megafauna that lived during the Pleistocene, and appears to have disappeared around 40,000 years ago. The first Aboriginal settlers of Australia may have encountered living Megalania.[1]

Megalania is the land-basedlizard known to have existed. Judging from its size, Megalania would have fed mostly upon medium- to large-sized animals, including any of the giant marsupials like Diprotodon .

Ralph Molnar in 2004 determined a range of possible sizes for Megalania. He did this by scaling up from dorsal vertebrae, after he determined a relationship between dorsal vertebrae length and total body length. If it had a long thin tail like the Lace monitor (Varanus varius), then it would have reached a length of 7.9 metres (26 ft). If its tail-to-body proportions were more similar to that of the Komodo dragon, then a length of around 7 metres (23 ft) is more likely. Using 7 m as the maximum length, Molnar estimated the average weight of the lizard at 320 kilograms (710 lb), and 1,940 kilograms (4,280 lb) as the maximum.[2]